Papers In Press, published online ahead of print June 23, 2008
J. Biol. Chem, 10.1074/jbc.M801946200
Submitted on March 11, 2008
Revised on June 23, 2008
Accepted on June 23, 2008
Crystal structure of soluble domain of malaria sporozoite protein UIS3 in complex with lipid
Ashwani Sharma, Manickam Yogavel, Reetesh Raj Akhouri, Jasmita Gill, and Amit Sharma
Structural and Computational Biology Group, International Centre for Genetic Engineering and Biotechnology, New Delhi, Delhi 110067
Corresponding Author: amit.icgeb{at}gmail.com
Malaria parasite UIS3 (Upregulated in Infective Sporozoites gene 3) is essential for sporozoite development in infected hepatocytes. UIS3 encodes for a membrane protein which is localized to the parasite parasitophorous vacuolar membrane in infected hepatocytes. We describe here 2.5Å resolution crystal structure of Plasmodium falciparum UIS3 soluble domain (PfUIS3130-229) in complex with the lipid phosphatidylethanolamine (PE). PfUIS3130-229 is a novel, compact and all
helical structure bound to one molecule of phosphatidylethanolamine (PE). The PfUIS3130-229-PE complex structure reveals a novel binding site with specific interactions between PfUIS3130-229and the PE head group. One acyl chain of PE wraps around part of PfUIS3130-229and docks onto a hydrophobic channel. We additionally provide new structural and biochemical evidence of PfUIS3130-229interactions with lipids (phosphatidylethanolamine), with phospholipid liposomes and with the human liver fatty acid binding protein (LFABP). The direct interaction of PfUIS3130-229with LFABP most likely provides the parasite with a conduit for importing essential fatty acids/lipids. Therefore, our analyses have implications for lipid transport into the parasite during the rapid growth phases of sporozoites. Given that PfUIS3 is essential for establishment of liver stage infection by P. falciparum, our data provide a new target for abrogating parasite development within liver cells before typical symptoms of malaria can manifest.